Under proper conditions of stimulation, very small electrical signals of inner retinal origin may be recorded selectively from humans and animals using non-invasive methods. These complement other tissue-specific signals (ERGs) which have been known for 50 years. Pattern dependent signals (PERRs) are recent discoveries and their use in disease related research will be hastened and improved if their physiology is well appreciated in highly developed mammalian retinas. The broad questions are: What are "safe" anesthetics and sedatives; and which cells and tissues are responding and how are they changed by lesions and early glaucoma. Specifically, we will use newly developed optical and electronic systems to excite and record local PERRs to determine: (1) Anesthetic/sedative agents that do not interact with these small potentials; (2) The contribution (if any) of the intraorbital optic nerve; (3) The relative signal input from glial elements; (4) "X-like" and "y-like" cell contributions; (5) Extent of influence of local inner retinal lesions on PERR contrast sensitivity of nearby "normal" regions; and (6) Apply PERR technology to the early study of developing of fields pathophysiology and histopathology of chronic open-angle glaucoma in the spontaneously glaucomatous Florida beagle model and the (laser induced) rhesus monkey model.